Deterioration determination apparatus for airflow meter and deterioration determination method

A deterioration determination apparatus for a thermal airflow meter measuring an intake air flow rate of an internal combustion engine, the deterioration determination apparatus determining a degree of deterioration in characteristics of the thermal airflow meter when a maintenance of a vehicle is conducted, comprising:

• a control means for controlling the engine in such a manner that a driving condition of the engine is brought into a specified condition;
• and
• a determining means for determining a degree of deterioration in characteristics of the thermal airflow meter by comparing a measurement error of the airflow meter with a specified determination value, wherein the measurement error is detected when the engine is at the specified condition;
• wherein:
• the control means adjusts an intake air flow rate of the engine so that the driving condition of the engine is brought into the specified condition;
• the internal combustion engine is provided with at least one of a variable valve timing controller and
• a variable valve lift controller, and the variable valve timing controller sets an advance quantity of a valve timing at a specified advance value, and the variable valve lift controller sets a valve lift at a specified lift value when the determining means determines the degree of deterioration.

A deterioration determination apparatus for a thermal airflow meter measuring an intake air flow rate of an internal combustion engine, the deterioration determination apparatus determining a degree of deterioration in characteristics of the thermal airflow meter when a maintenance of a vehicle is conducted, comprising:

• a control means for controlling the engine in such a manner that a driving condition of the engine is brought into a specified condition;
• and
• a determining means for determining a degree of deterioration in characteristics of the thermal airflow meter by comparing a measurement error of the airflow meter with a specified determination value, wherein the measurement error is detected when the engine is at the specified condition;
• wherein:
• the control means adjusts an intake air flow rate of the engine so that the driving condition of the engine is brought into the specified condition:
• the deterioration determination apparatus further comprises:
• a memory means for storing a previous maintenance time and a previous measurement error of the airflow meter;
• and
• a determination-value computing means for computing the specified determination value based on a present maintenance time, a present measurement error, the previous maintenance time and the previous measurement error.

A deterioration determination apparatus for a thermal airflow meter measuring an intake air flow rate of an internal combustion engine, the deterioration determination apparatus determining a degree of deterioration in characteristics of the thermal airflow meter when a maintenance of a vehicle is conducted, comprising:

• a control means for controlling the engine in such a manner that a driving condition of the engine is brought into a specified condition;
• and
• a determining means for determining a degree of deterioration in characteristics of the thermal airflow meter by comparing a measurement error of the airflow meter with a specified determination value, wherein the measurement error is detected when the engine is at the specified condition:
• wherein:
• the control means adjusts an intake air flow rate of the engine so that the driving condition of the engine is brought into the specified condition;
• the deterioration apparatus further comprises:
• a correction means for correcting the measurement error of the airflow meter based on an air temperature and an air pressure, wherein
• the measurement error of the airflow meter is computed based on the corrected measurement error.